This invention in general relates to a bed system. More particularly, this invention relates to a user support system for a bed, such as a mattress, which uses fluidizable granular material to support the user thereon.
The quality of sleep is generally influenced by the features of the mattress. The characteristics of a mattress affect the health of the user during the course of long time intervals. Important characteristics of the mattress can be considered to include reduced partial oppression, fitness for natural posture, stability in holding the user and potential for good ventilation.
In ordinary homes, water mattresses, air mattresses and gel mattresses are widely known as mattresses having a soft feel. Although these mattresses are simple in structure and are moderate in price, they have some problems which need to be overcome. These problems include several of:
(a) partial oppression caused by the tension of a sealed container holding the fluid; PA0 (b) deterioration of supported posture, caused by a difference in weight (or specific gravity) of regions of the body; PA0 (c) low stability in holding the body, resulting from high fluidity of the fluid; PA0 (d) lack of ventilation, due to the use of the sealed container; and PA0 (e) thermal disharmony caused by a large thermal capacity of a mass of water. PA0 (a) extra weight relating to buoyancy of the fluidized granular material; PA0 (b) extra energy consumed for thermal conditioning of the pressurized air; PA0 (c) deterioration of supported posture, caused by a difference in weight (or specific gravity) of regions of the body; and PA0 (d) unstable controllability in fluidizing the granular material, relating to the aerodynamics.
In the medical fields, fluidized beds are used for supporting the patient with little partial oppression. There are some problems associated with using fluidized beds in the home, including several of:
With respect to fluidized beds, the Goodwin patent (U.S. Pat. No. 4,637,083) discloses a fluidized patient support apparatus, the Eady patent (U.S. Pat. No. 4,951,335) discloses a mattress assembly, the Smith patent (U.S. Pat. No. 4,686,723) discloses a semi-fluidized bed, the Kato patent (U.S. Pat. No. 4,768,250) discloses a fluidized bead bed, the Romano patent (U.S. Pat. No. 5,539,943) discloses an apparatus and method for percussion of fluidized support surface and the Voelker patent (U.S. Pat. No. 3,840,920) discloses an adjustable mattress for pregnant mothers.